When to go bigger than stock 6.1 injectors?

[1fastsedan]

I'm hoping to start a discussion here about what level of HP requires going to bigger injectors, and if so which ones to use. I have been searching the forums and found this thread that did the same thing for the 5.7's.
http://www.lxforums.com/board/showth...=fuel+injector

I also checked the calculator link that JonW posted (http://www.rceng.com/technical.aspx) and put in numbers numbers that come out to 360cc/min at 59 psi. (the reference output of our injectors). This led me to a max of 510 HP AT THE CRANK!

Now, I don't know if this relationship is linear or not so bear with me. My stock 300C SRT8 dyno'd 365 RWHP, a 60 HP difference from crank to wheels (assuming 425 HP at the crank). That would put the danger zone somewhere around 450 RWHP. Right?

Discuss.

 

[HalV48]

Good question. We are doing that right now. With the B&G Stage II at 24.57 degrees of advance, I was running 13.77 A/F. We put in the SRT4 Stage 1's and I was 10.0 A/F. With CMR now at GSM we will be able to see what happens now with us being able to adjust the fuel maps. So we will see if we can fatten the stock injectors up enough, or see if we can lean the SRT4's down enough. Maybe both will work.

I'm hoping to start a discussion here about what level of HP requires going to bigger injectors, and if so which ones to use. I have been searching the forums and found this thread that did the same thing for the 5.7's.
http://www.lxforums.com/board/showth...=fuel+injector

I also checked the calculator link that JonW posted (http://www.rceng.com/technical.aspx) and put in numbers numbers that come out to 360cc/min at 59 psi. (the reference output of our injectors). This led me to a max of 510 HP AT THE CRANK!

Now, I don't know if this relationship is linear or not so bear with me. My stock 300C SRT8 dyno'd 365 RWHP, a 60 HP difference from crank to wheels (assuming 425 HP at the crank). That would put the danger zone somewhere around 450 RWHP. Right?

Discuss.

 

[1bad4dr]

Excellent topic bro...

It is known that the Stroker motors need larger injectors as do applications such as mine.

Question is, do you need larger injectors when a cam, P&P Heads, and Intake, LT Headers are added???

hmmmm...

 

[1fastsedan]

Ron (and/or Hal), what injectors are you currently running? Brand? Capacity?

 

[HalV48]

Ron (and/or Hal), what injectors are you currently running? Brand? Capacity?

I have stock in now, have had the Blue Top SRT4 Stage 1's.

HHP was advertising some 426 custom made injectors. You might want to check them out.

 

[1fastsedan]

HHP was advertising some 426 custom made injectors. You might want to check them out.

Holy Crap! They want $1200 for those injectors.

http://estore.websitepros.com/802805/Detail.bok?no=1315

I'm sure we as a group can come up with a more reasonable answer than that.

 

[1bad4dr]

I have always ran stock injectors.

I do have an MDS Boostapump that sends more voltage to the stock injectors for more fuel.

Now that Diablo's CMR tune is a reality, Scott (GSM) has been working diligently on the right tune with larger injectors for my application. Looks like we are only a couple of short weeks away from finalization. woot.

 

[Raland]

Does anyone know what pulsewidth the injectors are working at on stock engines with a predator or custom tune? That's going to tell you whether you need to start thinking about going bigger.
From all I've read you don't want to run injectors continuously at anything over 80% duty cycle. If HHP went to the expense of creating special injectors for 426's is seems likely the stock injectors max out at some point.

 

[1fastsedan]

Does anyone know what pulsewidth the injectors are working at on stock engines with a predator or custom tune? That's going to tell you whether you need to start thinking about going bigger.
From all I've read you don't want to run injectors continuously at anything over 80% duty cycle. If HHP went to the expense of creating special injectors for 426's is seems likely the stock injectors max out at some point.

I sent a PM to a tuner asking if they've watched the duty cycle at all, I'm waiting to hear back. That 510 BHP number came from the calculator on a fuel injector specialty site. That shop isn't too far away from me. Maybe I'll have to pay them a visit...

 

[Ozzie]

Josh at House of Power is working on a solution for replacement injectors. (A much more economical solution than those currently offered, BTW). Nothing available just yet, but stay tuned.

 

[1bad4dr]

Josh at House of Power is working on a solution for replacement injectors. (A much more economical solution than those currently offered, BTW). Nothing available just yet, but stay tuned.

Cool. Hopefully they will get the Vendorship here soon as well. Trojan also got the packet and was onsite when I emailed it to him.

 

[Trojan]

Cool. Hopefully they will get the Vendorship here soon as well. Trojan also got the packet and was onsite when I emailed it to him.

We had a long day tinkering around with tunes but tomorrow were gonna be testing some new injectors and some new tunes. Stayed tuned, well also get to that vendor sign up deal as well. :thumb2:

 

[srt8_hmi]

so what is the final verdict??? does a stroker motor require larger injectors???

 

[1fastsedan]

so what is the final verdict??? does a stroker motor require larger injectors???

Yes. I have a set of blue giant injectors for sale if you're interested.

 

[FLSRT8]

I'm currently researching injectors for my build. The first set I have are 93 Pd. I may have to go bigger.